[PATCH v3 1/8] ARM: KVM: Initial skeleton to compile KVM support

[Christoffer Dall <cdall@cs.columbia.edu>]

Targets KVM support for Cortex A-15 processors.

Contains no real functionality but all the framework components,
make files, header files and some tracing functionality.
---
 arch/arm/Kconfig                   |    2 
 arch/arm/Makefile                  |    1 
 arch/arm/include/asm/kvm.h         |   65 +++++
 arch/arm/include/asm/kvm_asm.h     |   28 ++
 arch/arm/include/asm/kvm_emulate.h |   89 +++++++
 arch/arm/include/asm/kvm_host.h    |  114 +++++++++
 arch/arm/include/asm/kvm_para.h    |    9 +
 arch/arm/include/asm/unified.h     |   12 +
 arch/arm/kvm/Kconfig               |   44 ++++
 arch/arm/kvm/Makefile              |   13 +
 arch/arm/kvm/arm.c                 |  363 ++++++++++++++++++++++++++++++
 arch/arm/kvm/arm_emulate.c         |   70 ++++++
 arch/arm/kvm/arm_guest.c           |  142 ++++++++++++
 arch/arm/kvm/arm_interrupts.S      |   17 +
 arch/arm/kvm/arm_mmu.c             |    0 
 arch/arm/kvm/trace.c               |  436 ++++++++++++++++++++++++++++++++++++
 arch/arm/kvm/trace.h               |  108 +++++++++
 arch/arm/mach-vexpress/Kconfig     |    1 
 arch/arm/mm/Kconfig                |    7 +
 include/linux/kvm.h                |    1 
 20 files changed, 1522 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/include/asm/kvm.h
 create mode 100644 arch/arm/include/asm/kvm_asm.h
 create mode 100644 arch/arm/include/asm/kvm_emulate.h
 create mode 100644 arch/arm/include/asm/kvm_host.h
 create mode 100644 arch/arm/include/asm/kvm_para.h
 create mode 100644 arch/arm/kvm/Kconfig
 create mode 100644 arch/arm/kvm/Makefile
 create mode 100644 arch/arm/kvm/arm.c
 create mode 100644 arch/arm/kvm/arm_emulate.c
 create mode 100644 arch/arm/kvm/arm_guest.c
 create mode 100644 arch/arm/kvm/arm_interrupts.S
 create mode 100644 arch/arm/kvm/arm_mmu.c
 create mode 100644 arch/arm/kvm/trace.c
 create mode 100644 arch/arm/kvm/trace.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b410049..b2a2b65 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1951,3 +1951,5 @@ source "security/Kconfig"
 source "crypto/Kconfig"
 
 source "lib/Kconfig"
+
+source "arch/arm/kvm/Kconfig"
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 6f7b292..72335fc 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -254,6 +254,7 @@ core-$(CONFIG_VFP)		+= arch/arm/vfp/
 
 # If we have a machine-specific directory, then include it in the build.
 core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
+core-$(CONFIG_KVM) 		+= arch/arm/kvm/
 core-y				+= $(machdirs) $(platdirs)
 
 drivers-$(CONFIG_OPROFILE)      += arch/arm/oprofile/
diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
new file mode 100644
index 0000000..8311198
--- /dev/null
+++ b/arch/arm/include/asm/kvm.h
@@ -0,0 +1,65 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#ifndef __ARM_KVM_H__
+#define __ARM_KVM_H__
+
+#include <asm/types.h>
+
+/*
+ * Modes used for short-hand mode determinition in the world-switch code and
+ * in emulation code.
+ *
+ * Note: These indices do NOT correspond to the value of the CPSR mode bits!
+ */
+#define MODE_FIQ	0
+#define MODE_IRQ	1
+#define MODE_SVC	2
+#define MODE_ABT	3
+#define MODE_UND	4
+#define MODE_USR	5
+#define MODE_SYS	6
+
+struct kvm_regs {
+	__u32 regs0_7[8];	/* Unbanked regs. (r0 - r7)	   */
+	__u32 fiq_regs8_12[5];	/* Banked fiq regs. (r8 - r12)	   */
+	__u32 usr_regs8_12[5];	/* Banked usr registers (r8 - r12) */
+	__u32 reg13[6];		/* Banked r13, indexed by MODE_	   */
+	__u32 reg14[6];		/* Banked r13, indexed by MODE_	   */
+	__u32 reg15;
+	__u32 cpsr;
+	__u32 spsr[5];		/* Banked SPSR,  indexed by MODE_  */
+	struct {
+		__u32 c2_base0;
+		__u32 c2_base1;
+		__u32 c3_dacr;
+	} cp15;
+
+};
+
+struct kvm_sregs {
+};
+
+struct kvm_fpu {
+};
+
+struct kvm_guest_debug_arch {
+};
+
+struct kvm_debug_exit_arch {
+};
+
+#endif /* __ARM_KVM_H__ */
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
new file mode 100644
index 0000000..c3d4458
--- /dev/null
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -0,0 +1,28 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#ifndef __ARM_KVM_ASM_H__
+#define __ARM_KVM_ASM_H__
+
+#define ARM_EXCEPTION_RESET	  0
+#define ARM_EXCEPTION_UNDEFINED   1
+#define ARM_EXCEPTION_SOFTWARE    2
+#define ARM_EXCEPTION_PREF_ABORT  3
+#define ARM_EXCEPTION_DATA_ABORT  4
+#define ARM_EXCEPTION_IRQ	  5
+#define ARM_EXCEPTION_FIQ	  6
+
+#endif /* __ARM_KVM_ASM_H__ */
diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
new file mode 100644
index 0000000..8eed752
--- /dev/null
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -0,0 +1,89 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#ifndef __ARM_KVM_EMULATE_H__
+#define __ARM_KVM_EMULATE_H__
+
+#include <linux/kvm_host.h>
+#include <asm/kvm_asm.h>
+
+u32* kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
+
+static inline unsigned char vcpu_mode(struct kvm_vcpu *vcpu)
+{
+	u8 modes_table[16] = {
+		MODE_USR,	// 0x0
+		MODE_FIQ,	// 0x1
+		MODE_IRQ,	// 0x2
+		MODE_SVC,	// 0x3
+		0xf, 0xf, 0xf,
+		MODE_ABT,	// 0x7
+		0xf, 0xf, 0xf,
+		MODE_UND,	// 0xb
+		0xf, 0xf, 0xf,
+		MODE_SYS};	// 0xf
+
+	BUG_ON(modes_table[vcpu->arch.regs.cpsr & 0xf] == 0xf);
+	return modes_table[vcpu->arch.regs.cpsr & 0xf];
+}
+
+/*
+ * Return the SPSR for the specified mode of the virtual CPU.
+ */
+static inline u32 kvm_vcpu_spsr(struct kvm_vcpu *vcpu, u32 mode)
+{
+	switch (mode) {
+	case MODE_SVC:
+		return vcpu->arch.regs.svc_regs[2];
+	case MODE_ABT:
+		return vcpu->arch.regs.svc_regs[2];
+	case MODE_UND:
+		return vcpu->arch.regs.svc_regs[2];
+	case MODE_IRQ:
+		return vcpu->arch.regs.svc_regs[2];
+	case MODE_FIQ:
+		return vcpu->arch.regs.fiq_regs[7];
+	default:
+		BUG();
+	}
+}
+
+/* Get vcpu register for current mode */
+#define vcpu_reg(_vcpu, _reg_num) \
+	(*kvm_vcpu_reg((_vcpu), _reg_num, vcpu_mode(_vcpu)))
+
+/* Get vcpu register for specific mode */
+#define vcpu_reg_m(_vcpu, _reg_num, _mode) \
+	(*kvm_vcpu_reg(_vcpu, _reg_num, _mode))
+
+#define vcpu_cpsr(_vcpu) \
+	(_vcpu->arch.regs.cpsr)
+
+/* Get vcpu SPSR for current mode */
+#define vcpu_spsr(_vcpu) \
+	kvm_vcpu_spsr(_vcpu, vcpu_mode(_vcpu))
+
+/* Get vcpu SPSR for specific mode */
+#define vcpu_spsr_m(_vcpu, _mode) \
+	kvm_vcpu_spsr(_vcpu, _mode)
+
+#define MODE_HAS_SPSR(_vcpu) \
+	 ((vcpu_mode(_vcpu)) < MODE_USR)
+
+#define VCPU_MODE_PRIV(_vcpu) \
+	(((vcpu_mode(_vcpu)) == MODE_USR) ? 0 : 1)
+
+#endif /* __ARM_KVM_EMULATE_H__ */
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
new file mode 100644
index 0000000..6e8a08d
--- /dev/null
+++ b/arch/arm/include/asm/kvm_host.h
@@ -0,0 +1,114 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#ifndef __ARM_KVM_HOST_H__
+#define __ARM_KVM_HOST_H__
+
+#define KVM_MAX_VCPUS 1
+#define KVM_MEMORY_SLOTS 32
+#define KVM_PRIVATE_MEM_SLOTS 4
+#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+
+/* We don't currently support large pages. */
+#define KVM_HPAGE_GFN_SHIFT(x)	0
+#define KVM_NR_PAGE_SIZES	1
+#define KVM_PAGES_PER_HPAGE(x)	(1UL<<31)
+
+struct kvm_vcpu;
+u32* kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
+
+struct kvm_arch {
+};
+
+#define EXCEPTION_NONE      0
+#define EXCEPTION_RESET     0x80
+#define EXCEPTION_UNDEFINED 0x40
+#define EXCEPTION_SOFTWARE  0x20
+#define EXCEPTION_PREFETCH  0x10
+#define EXCEPTION_DATA      0x08
+#define EXCEPTION_IMPRECISE 0x04
+#define EXCEPTION_IRQ       0x02
+#define EXCEPTION_FIQ       0x01
+
+struct kvm_vcpu_regs {
+	u32 usr_regs[15];	/* R0_usr - R14_usr */
+	u32 svc_regs[3];	/* SP_svc, LR_svc, SPSR_svc */
+	u32 abt_regs[3];	/* SP_abt, LR_abt, SPSR_abt */
+	u32 und_regs[3];	/* SP_und, LR_und, SPSR_und */
+	u32 irq_regs[3];	/* SP_irq, LR_irq, SPSR_irq */
+	u32 fiq_regs[8];	/* R8_fiq - R14_fiq, SPSR_fiq */
+	u32 pc;			/* The program counter (r15) */
+	u32 cpsr;		/* Guest emulated CPSR */
+} __packed;
+
+struct kvm_vcpu_arch {
+	/* Pointer to regs struct on shared page */
+	struct kvm_vcpu_regs regs;
+
+	/* Pointer to cached mode on shared page */
+	unsigned long *mode;
+
+	/* System control coprocessor (cp15) */
+	struct {
+		u32 c1_SCTLR;		/* System Control Register */
+		u32 c1_ACTLR;		/* Auxilliary Control Register */
+		u32 c1_CPACR;		/* Coprocessor Access Control Register */
+		u64 c2_TTBR0;		/* Translation Table Base Register 0 */
+		u64 c2_TTBR1;		/* Translation Table Base Register 1 */
+		u32 c2_TTBCR;		/* Translation Table Base Control Register */
+		u32 c3_DACR;		/* Domain Access Control Register */
+	} cp15;
+
+	u32 exception_pending;  	/* Exception to raise after emulation */
+
+	/* Exception Information */
+	u32 hsr;		/* Hyp Syndrom Register */
+	u32 hdfar;		/* Hyp Data Fault Address Register */
+	u32 hifar;		/* Hyp Inst. Fault Address Register */
+	u32 hpfar;		/* Hyp IPA Fault Address Register */
+
+	/* IO related fields */
+	u32 mmio_rd;
+
+	/* Misc. fields */
+	u32 wait_for_interrupts;
+};
+
+struct kvm_vm_stat {
+	u32 remote_tlb_flush;
+};
+
+struct kvm_vcpu_stat {
+	u32 sum_exits;
+	u32 mmio_exits;
+	u32 dcr_exits;
+	u32 signal_exits;
+	u32 light_exits;
+	/* Account for special types of light exits: */
+	u32 itlb_real_miss_exits;
+	u32 itlb_virt_miss_exits;
+	u32 dtlb_real_miss_exits;
+	u32 dtlb_virt_miss_exits;
+	u32 syscall_exits;
+	u32 isi_exits;
+	u32 dsi_exits;
+	u32 emulated_inst_exits;
+	u32 dec_exits;
+	u32 ext_intr_exits;
+	u32 halt_wakeup;
+};
+
+#endif /* __ARM_KVM_HOST_H__ */
diff --git a/arch/arm/include/asm/kvm_para.h b/arch/arm/include/asm/kvm_para.h
new file mode 100644
index 0000000..7ce5f1c
--- /dev/null
+++ b/arch/arm/include/asm/kvm_para.h
@@ -0,0 +1,9 @@
+#ifndef _ASM_X86_KVM_PARA_H
+#define _ASM_X86_KVM_PARA_H
+
+static inline unsigned int kvm_arch_para_features(void)
+{
+	return 0;
+}
+
+#endif /* _ASM_X86_KVM_PARA_H */
diff --git a/arch/arm/include/asm/unified.h b/arch/arm/include/asm/unified.h
index bc63116..14ad6bb 100644
--- a/arch/arm/include/asm/unified.h
+++ b/arch/arm/include/asm/unified.h
@@ -54,6 +54,18 @@
 
 #endif	/* CONFIG_THUMB2_KERNEL */
 
+#ifdef CONFIG_KVM
+#ifdef __ASSEMBLY__
+.arch_extension sec
+.arch_extension virt
+#else
+__asm__(
+"	.arch_extension sec\n"
+"	.arch_extension virt\n"
+);
+#endif
+#endif
+
 #ifndef CONFIG_ARM_ASM_UNIFIED
 
 /*
diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
new file mode 100644
index 0000000..1806a6d
--- /dev/null
+++ b/arch/arm/kvm/Kconfig
@@ -0,0 +1,44 @@
+#
+# KVM configuration
+#
+
+source "virt/kvm/Kconfig"
+
+menuconfig VIRTUALIZATION
+	bool "Virtualization"
+	---help---
+	  Say Y here to get to see options for using your Linux host to run
+	  other operating systems inside virtual machines (guests).
+	  This option alone does not add any kernel code.
+
+	  If you say N, all options in this submenu will be skipped and
+	  disabled.
+
+if VIRTUALIZATION
+
+config KVM
+	bool "Kernel-based Virtual Machine (KVM) support"
+	select PREEMPT_NOTIFIERS
+	select ANON_INODES
+	select KVM_ARM_HOST
+	select KVM_MMIO
+	---help---
+	  Support hosting virtualized guest machines. You will also
+	  need to select one or more of the processor modules below.
+
+	  This module provides access to the hardware capabilities through
+	  a character device node named /dev/kvm.
+
+	  If unsure, say N.
+
+config KVM_ARM_HOST
+	bool "KVM host support for ARM cpus."
+	depends on KVM
+	depends on MMU
+	depends on CPU_V7 || ARM_VIRT_EXT
+	---help---
+	  Provides host support for ARM processors.
+
+source drivers/virtio/Kconfig
+
+endif # VIRTUALIZATION
diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
new file mode 100644
index 0000000..4ff905d
--- /dev/null
+++ b/arch/arm/kvm/Makefile
@@ -0,0 +1,13 @@
+#
+# Makefile for Kernel-based Virtual Machine module
+#
+
+EXTRA_CFLAGS += -Ivirt/kvm -Iarch/arm/kvm
+AFLAGS_arm_interrupts.o := -I$(obj)
+
+kvm-arm-y += $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o)
+
+kvm-arm-y += arm.o arm_guest.o arm_interrupts.o arm_mmu.o arm_emulate.o \
+		trace.o
+
+obj-$(CONFIG_KVM) += kvm-arm.o
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
new file mode 100644
index 0000000..2157c1e
--- /dev/null
+++ b/arch/arm/kvm/arm.c
@@ -0,0 +1,363 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/mman.h>
+#include <asm/uaccess.h>
+#include <asm/ptrace.h>
+#include <asm/mman.h>
+
+#include "trace.h"
+
+int kvm_arch_hardware_enable(void *garbage)
+{
+	return 0;
+}
+
+void kvm_arch_hardware_disable(void *garbage)
+{
+}
+
+int kvm_arch_hardware_setup(void)
+{
+	return 0;
+}
+
+void kvm_arch_hardware_unsetup(void)
+{
+}
+
+void kvm_arch_check_processor_compat(void *rtn)
+{
+	*(int *)rtn = 0;
+}
+
+void kvm_arch_sync_events(struct kvm *kvm)
+{
+}
+
+int kvm_arch_init_vm(struct kvm *kvm)
+{
+	return 0;
+}
+
+void kvm_arch_destroy_vm(struct kvm *kvm)
+{
+	int i;
+
+	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+		if (kvm->vcpus[i]) {
+			kvm_arch_vcpu_free(kvm->vcpus[i]);
+			kvm->vcpus[i] = NULL;
+		}
+	}
+}
+
+int kvm_dev_ioctl_check_extension(long ext)
+{
+	int r;
+	switch (ext) {
+	case KVM_CAP_USER_MEMORY:
+	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
+		r = 1;
+		break;
+	case KVM_CAP_COALESCED_MMIO:
+		r = KVM_COALESCED_MMIO_PAGE_OFFSET;
+		break;
+	default:
+		r = 0;
+		break;
+	}
+	return r;
+}
+
+long kvm_arch_dev_ioctl(struct file *filp,
+			unsigned int ioctl, unsigned long arg)
+{
+	int ret = 0;
+
+	switch (ioctl) {
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret < 0)
+		printk(KERN_ERR "error processing ARM ioct: %d", ret);
+	return ret;
+}
+
+int kvm_arch_set_memory_region(struct kvm *kvm,
+			       struct kvm_userspace_memory_region *mem,
+			       struct kvm_memory_slot old,
+			       int user_alloc)
+{
+	return 0;
+}
+
+int kvm_arch_prepare_memory_region(struct kvm *kvm,
+				   struct kvm_memory_slot *memslot,
+				   struct kvm_memory_slot old,
+				   struct kvm_userspace_memory_region *mem,
+				   int user_alloc)
+{
+	return 0;
+}
+
+void kvm_arch_commit_memory_region(struct kvm *kvm,
+				   struct kvm_userspace_memory_region *mem,
+				   struct kvm_memory_slot old,
+				   int user_alloc)
+{
+}
+
+void kvm_arch_flush_shadow(struct kvm *kvm)
+{
+	// XXX What should this do?
+}
+
+struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
+{
+	int err;
+	struct kvm_vcpu *vcpu;
+
+	vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
+	if (!vcpu) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = kvm_vcpu_init(vcpu, kvm, id);
+	if (err)
+		goto free_vcpu;
+
+	return vcpu;
+free_vcpu:
+	kmem_cache_free(kvm_vcpu_cache, vcpu);
+out:
+	return ERR_PTR(err);
+}
+
+void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
+{
+	KVMARM_NOT_IMPLEMENTED();
+}
+
+void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
+{
+	kvm_arch_vcpu_free(vcpu);
+}
+
+int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
+int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
+{
+	KVMARM_NOT_IMPLEMENTED();
+	return 0;
+}
+
+void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+}
+
+void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+}
+
+void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
+{
+}
+
+int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
+                                        struct kvm_guest_debug *dbg)
+{
+	return -EINVAL;
+}
+
+
+int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
+				    struct kvm_mp_state *mp_state)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
+				    struct kvm_mp_state *mp_state)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
+{
+	return 0;
+}
+
+int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	KVMARM_NOT_IMPLEMENTED();
+	return -EINVAL;
+}
+
+static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
+				    struct kvm_interrupt *intr)
+{
+	u32 mask;
+
+	switch (intr->irq) {
+	case EXCEPTION_IRQ:
+		/* IRQ */
+		mask = EXCEPTION_IRQ;
+		break;
+	case EXCEPTION_FIQ:
+		/* FIQ */
+		mask = EXCEPTION_FIQ;
+		break;
+	default:
+		/* Only async exceptions are supported here */
+		return -EINVAL;
+	}
+
+	if (intr->raise) {
+		if (mask == EXCEPTION_IRQ)
+			kvm_trace_activity(101, "raise IRQ");
+		else if (mask == EXCEPTION_FIQ)
+			kvm_trace_activity(102, "raise FIQ");
+		vcpu->arch.exception_pending |= mask;
+		vcpu->arch.wait_for_interrupts = 0;
+	} else {
+		if (mask == EXCEPTION_IRQ)
+			kvm_trace_activity(103, "lower IRQ");
+		else if (mask == EXCEPTION_FIQ)
+			kvm_trace_activity(104, "lower FIQ");
+
+		vcpu->arch.exception_pending &= ~mask;
+	}
+
+	return 0;
+}
+
+long kvm_arch_vcpu_ioctl(struct file *filp,
+			 unsigned int ioctl, unsigned long arg)
+{
+	struct kvm_vcpu *vcpu = filp->private_data;
+	void __user *argp = (void __user *)arg;
+	int r;
+
+	switch (ioctl) {
+	case KVM_S390_STORE_STATUS: {
+		return -EINVAL;
+	}
+	case KVM_INTERRUPT: {
+		struct kvm_interrupt intr;
+
+		r = -EFAULT;
+		if (copy_from_user(&intr, argp, sizeof intr))
+			break;
+		r = kvm_vcpu_ioctl_interrupt(vcpu, &intr);
+		break;
+	}
+	default:
+		r = -EINVAL;
+	}
+
+	return r;
+}
+
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+	return -ENOTSUPP;
+}
+
+long kvm_arch_vm_ioctl(struct file *filp,
+		       unsigned int ioctl, unsigned long arg)
+{
+	printk(KERN_ERR "kvm_arch_vm_ioctl: Unsupported ioctl (%d)\n", ioctl);
+	return -EINVAL;
+}
+
+int kvm_arch_init(void *opaque)
+{
+	return 0;
+}
+
+void kvm_arch_exit(void)
+{
+}
+
+static int k_show(struct seq_file *m, void *v)
+{
+	print_kvm_debug_info(&seq_printf, m);
+	return 0;
+}
+
+static void *k_start(struct seq_file *m, loff_t *pos)
+{
+	return *pos < 1 ? (void *)1 : NULL;
+}
+
+static void *k_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	++*pos;
+	return NULL;
+}
+
+static void k_stop(struct seq_file *m, void *v)
+{
+}
+
+static const struct seq_operations kvmproc_op = {
+	.start	= k_start,
+	.next	= k_next,
+	.stop	= k_stop,
+	.show	= k_show
+};
+
+static int kvm_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &kvmproc_op);
+}
+
+static const struct file_operations proc_kvm_operations = {
+	.open		= kvm_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int arm_init(void)
+{
+	int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	if (rc == 0)
+		proc_create("kvm", 0, NULL, &proc_kvm_operations);
+	return rc;
+}
+
+static void __exit arm_exit(void)
+{
+	kvm_exit();
+}
+
+module_init(arm_init);
+module_exit(arm_exit)
diff --git a/arch/arm/kvm/arm_emulate.c b/arch/arm/kvm/arm_emulate.c
new file mode 100644
index 0000000..3dd4f08
--- /dev/null
+++ b/arch/arm/kvm/arm_emulate.c
@@ -0,0 +1,70 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#include <asm/kvm_emulate.h>
+
+/*
+ * Return a pointer to the register number valid in the specified mode of
+ * the virtual CPU.
+ */
+u32* kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
+{
+	struct kvm_vcpu_regs *regs;
+	u8 reg_idx;
+	BUG_ON(reg_num > 15);
+
+	regs = &vcpu->arch.regs;
+
+	/* The PC is trivial */
+	if (reg_num == 15)
+		return &(regs->pc);
+
+	/* Non-banked registers */
+	if (reg_num < 8)
+		return &(regs->usr_regs[reg_num]);
+
+	/* Banked registers r13 and r14 */
+	if (reg_num >= 13) {
+		reg_idx = reg_num - 13; /* 0=r13 and 1=r14 */
+		switch (mode) {
+		case MODE_FIQ:
+			return &(regs->fiq_regs[reg_idx + 5]);
+		case MODE_IRQ:
+			return &(regs->irq_regs[reg_idx]);
+		case MODE_SVC:
+			return &(regs->svc_regs[reg_idx]);
+		case MODE_ABT:
+			return &(regs->abt_regs[reg_idx]);
+		case MODE_UND:
+			return &(regs->und_regs[reg_idx]);
+		case MODE_USR:
+		case MODE_SYS:
+			return &(regs->usr_regs[reg_idx]);
+		}
+	}
+
+	/* Banked FIQ registers r8-r12 */
+	if (reg_num >= 8 && reg_num <= 12) {
+		if (mode == MODE_FIQ) {
+			reg_idx = reg_num - 8; /* 0=r8, ..., 4=r12 */
+			return &(regs->fiq_regs[reg_idx]);
+		} else
+			return &(regs->usr_regs[reg_num]);
+	}
+
+	BUG();
+	return NULL;
+}
diff --git a/arch/arm/kvm/arm_guest.c b/arch/arm/kvm/arm_guest.c
new file mode 100644
index 0000000..646f60c
--- /dev/null
+++ b/arch/arm/kvm/arm_guest.c
@@ -0,0 +1,142 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <asm/uaccess.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
+
+
+#define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
+#define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
+
+struct kvm_stats_debugfs_item debugfs_entries[] = {
+};
+
+int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
+int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+	struct kvm_vcpu_regs *vcpu_regs = &vcpu->arch.regs;
+
+	/*
+	 * GPRs and PSRs
+	 */
+	memcpy(regs->regs0_7, &(vcpu_regs->usr_regs[0]), sizeof(u32) * 8);
+	memcpy(regs->usr_regs8_12, &(vcpu_regs->usr_regs[8]), sizeof(u32) * 5);
+	memcpy(regs->fiq_regs8_12, &(vcpu_regs->fiq_regs[0]), sizeof(u32) * 5);
+	regs->reg13[MODE_FIQ] = vcpu_regs->fiq_regs[5];
+	regs->reg14[MODE_FIQ] = vcpu_regs->fiq_regs[6];
+	regs->reg13[MODE_IRQ] = vcpu_regs->irq_regs[0];
+	regs->reg14[MODE_IRQ] = vcpu_regs->irq_regs[1];
+	regs->reg13[MODE_SVC] = vcpu_regs->svc_regs[0];
+	regs->reg14[MODE_SVC] = vcpu_regs->svc_regs[1];
+	regs->reg13[MODE_ABT] = vcpu_regs->abt_regs[0];
+	regs->reg14[MODE_ABT] = vcpu_regs->abt_regs[1];
+	regs->reg13[MODE_UND] = vcpu_regs->und_regs[0];
+	regs->reg14[MODE_UND] = vcpu_regs->und_regs[1];
+	regs->reg13[MODE_USR] = vcpu_regs->usr_regs[0];
+	regs->reg14[MODE_USR] = vcpu_regs->usr_regs[1];
+
+	regs->spsr[MODE_FIQ]  = vcpu_regs->fiq_regs[7];
+	regs->spsr[MODE_IRQ]  = vcpu_regs->irq_regs[2];
+	regs->spsr[MODE_SVC]  = vcpu_regs->svc_regs[2];
+	regs->spsr[MODE_ABT]  = vcpu_regs->abt_regs[2];
+	regs->spsr[MODE_UND]  = vcpu_regs->und_regs[2];
+
+	regs->reg15 = vcpu_regs->pc;
+	regs->cpsr = vcpu_regs->cpsr;
+
+
+	/*
+	 * Co-processor registers.
+	 */
+	regs->cp15.c2_base0 = vcpu->arch.cp15.c2_TTBR0;
+	regs->cp15.c2_base1 = vcpu->arch.cp15.c2_TTBR1;
+	regs->cp15.c3_dacr = vcpu->arch.cp15.c3_DACR;
+
+	return 0;
+}
+
+int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+	struct kvm_vcpu_regs *vcpu_regs = &vcpu->arch.regs;
+
+	memcpy(&(vcpu_regs->usr_regs[0]), regs->regs0_7, sizeof(u32) * 8);
+	memcpy(&(vcpu_regs->usr_regs[8]), regs->usr_regs8_12, sizeof(u32) * 5);
+	memcpy(&(vcpu_regs->fiq_regs[0]), regs->fiq_regs8_12, sizeof(u32) * 5);
+
+	vcpu_regs->fiq_regs[5] = regs->reg13[MODE_FIQ];
+	vcpu_regs->fiq_regs[6] = regs->reg14[MODE_FIQ];
+	vcpu_regs->irq_regs[0] = regs->reg13[MODE_IRQ];
+	vcpu_regs->irq_regs[1] = regs->reg14[MODE_IRQ];
+	vcpu_regs->svc_regs[0] = regs->reg13[MODE_SVC];
+	vcpu_regs->svc_regs[1] = regs->reg14[MODE_SVC];
+	vcpu_regs->abt_regs[0] = regs->reg13[MODE_ABT];
+	vcpu_regs->abt_regs[1] = regs->reg14[MODE_ABT];
+	vcpu_regs->und_regs[0] = regs->reg13[MODE_UND];
+	vcpu_regs->und_regs[1] = regs->reg14[MODE_UND];
+	vcpu_regs->usr_regs[0] = regs->reg13[MODE_USR];
+	vcpu_regs->usr_regs[1] = regs->reg14[MODE_USR];
+
+	vcpu_regs->fiq_regs[7] = regs->spsr[MODE_FIQ];
+	vcpu_regs->irq_regs[2] = regs->spsr[MODE_IRQ];
+	vcpu_regs->svc_regs[2] = regs->spsr[MODE_SVC];
+	vcpu_regs->abt_regs[2] = regs->spsr[MODE_ABT];
+	vcpu_regs->und_regs[2] = regs->spsr[MODE_UND];
+
+	vcpu_regs->pc = regs->reg15;
+	vcpu_regs->cpsr = regs->cpsr;
+
+	return 0;
+}
+
+int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
+				  struct kvm_sregs *sregs)
+{
+	return -ENOTSUPP;
+}
+
+int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
+				  struct kvm_sregs *sregs)
+{
+	return -ENOTSUPP;
+}
+
+int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
+{
+	return -ENOTSUPP;
+}
+
+int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
+{
+	return -ENOTSUPP;
+}
+
+/* 'linear_address' is actually an encoding of AS|PID|EADDR . */
+int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
+				  struct kvm_translation *tr)
+{
+	return 0;
+}
diff --git a/arch/arm/kvm/arm_interrupts.S b/arch/arm/kvm/arm_interrupts.S
new file mode 100644
index 0000000..073a494
--- /dev/null
+++ b/arch/arm/kvm/arm_interrupts.S
@@ -0,0 +1,17 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+#include <asm/asm-offsets.h>
+#include <asm/kvm_asm.h>
diff --git a/arch/arm/kvm/arm_mmu.c b/arch/arm/kvm/arm_mmu.c
new file mode 100644
index 0000000..e69de29
diff --git a/arch/arm/kvm/trace.c b/arch/arm/kvm/trace.c
new file mode 100644
index 0000000..8ea1155
--- /dev/null
+++ b/arch/arm/kvm/trace.c
@@ -0,0 +1,436 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+#include <linux/types.h>
+#include <linux/kvm_types.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_emulate.h>
+#include "trace.h"
+
+
+/******************************************************************************
+ * Simple event counting
+ */
+
+struct kvm_event {
+	unsigned long long cnt;
+	char *descr;
+};
+
+static struct kvm_event kvm_eventc_log[KVM_EVENTC_ITEMS] =
+{
+	{ 0, "switch to guest" },
+	{ 0, "exit from guest" },
+	{ 0, "Block VCPU" },
+	{ 0, "Exit to QEMU for IRQ window" },
+	{ 0, "Switch VCPU mode" },
+	{ 0, "VCPU IRQs on" },
+	{ 0, "VCPU IRQs off" },
+	{ 0, "Wait-for-interrupts" },
+	{ 0, "Flush shadow page table" },
+	{ 0, "Virtual TTBR change" },
+	{ 0, "Read guest page table entry" },
+	{ 0, "Map GVA to GFN" },
+	{ 0, "Virtual DACR change" },
+	{ 0, "VCPU switch to privileged mode" },
+	{ 0, "VCPU switch from privileged mode" },
+	{ 0, "VCPU process ID registers change" },
+	{ 0, "Emulate Load/Store with translation" },
+	{ 0, "Emulate MRS" },
+	{ 0, "Emulate MSR" },
+	{ 0, "Emulate CPS" },
+	{ 0, "Need reschedule in execution loop" },
+	{ 0, "MCR 7,  5, 0 - Invalidate entire I-cache" },
+	{ 0, "MCR 7,  5, 1 - Invalidate line in I-cache MVA" },
+	{ 0, "MCR 7,  5, 2 - Invalidate line in I-cache set/way" },
+	{ 0, "MCR 7,  5, 7 - Flush branch target cache - MVA" },
+	{ 0, "MCR 7,  6, 0 - Invalidate entire data cache" },
+	{ 0, "MCR 7,  6, 1 - Invalidate data cache line - MVA" },
+	{ 0, "MCR 7,  6, 2 - Invalidate data cache line - set/way" },
+	{ 0, "MCR 7,  7, 0 - Invalidate D- and I-cache" },
+	{ 0, "MCR 7, 10, 0 - Clean entire data cache" },
+	{ 0, "MCR 7, 10, 1 - Clean data cache line - MVA" },
+	{ 0, "MCR 7, 10, 4 - Data Synchronization Barrier (DSB)" },
+	{ 0, "MCR 7, 14, 0 - Clean and invalidate entire D-cache" },
+	{ 0, "MCR 7, 14, 1 - Clean and invalidate D-cache line - MVA" },
+	{ 0, "MCR 7, 15, 0 - Clean and invalidate unified cache" },
+	{ 0, "MCR 8,  5, 0 - Invalidate instruction TLB" },
+	{ 0, "MCR 8,  6, 0 - Invalidate data TLB" },
+	{ 0, "MCR 8,  7, 0 - Invalidate unified TLB" },
+	{ 0, "Emulate Load-Store multiple" },
+};
+
+void kvm_arm_count_event(unsigned int event)
+{
+	if (event >= KVM_EVENTC_ITEMS)
+		return;
+
+	kvm_eventc_log[event].cnt++;
+}
+
+void kvm_arm_init_eventc(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < KVM_EVENTC_ITEMS; i++)
+		kvm_eventc_log[i].cnt = 0;
+}
+
+struct kvm_event_order {
+	struct kvm_event *event;
+	struct kvm_event_order *next;
+	struct kvm_event_order *prev;
+};
+static struct kvm_event_order event_order[KVM_EVENTC_ITEMS];
+
+static struct kvm_event_order *sort_kvm_event_log(void)
+{
+	unsigned int i;
+	struct kvm_event_order *ptr;
+	struct kvm_event_order head =
+		{ .event = NULL, .next = &head, .prev = &head };
+
+	for (i = 0; i < KVM_EVENTC_ITEMS; i++) {
+		event_order[i].event = &kvm_eventc_log[i];
+		ptr = head.next;
+		while (ptr->event != NULL &&
+		       ptr->event->cnt > kvm_eventc_log[i].cnt) {
+			ptr = ptr->next;
+		}
+		ptr->prev->next = &event_order[i];
+		event_order[i].prev = ptr->prev;
+		event_order[i].next = ptr;
+		ptr->prev = &event_order[i];
+	}
+
+	head.prev->next = NULL; /* Mark end of linked list */
+	return head.next;
+}
+
+/******************************************************************************
+ * Trace ring-buffer local to KVM/ARM
+ */
+
+#define KVM_TRACE_ACTIVITY
+#ifndef KVM_TRACE_ACTIVITY
+void kvm_trace_activity(unsigned int activity, char *fmt, ...)
+{
+}
+#else
+
+#define ACTIVITY_TRACE_ITEMS 50
+#define TRACE_DESCR_LEN 80
+static u32 activity_trace[ACTIVITY_TRACE_ITEMS];
+static u32 activity_trace_cnt[ACTIVITY_TRACE_ITEMS];
+static char activity_trace_descr[ACTIVITY_TRACE_ITEMS][TRACE_DESCR_LEN];
+static int activity_trace_index = 0;
+static bool trace_init = false;
+
+void kvm_trace_activity(unsigned int activity, char *fmt, ...)
+{
+	va_list ap;
+	unsigned int i;
+	char *ptr;
+
+	if (!trace_init) {
+		for (i = 0; i < ACTIVITY_TRACE_ITEMS; i++)
+			activity_trace_descr[i][0] = '\0';
+		trace_init = true;
+	}
+
+	if (activity_trace[activity_trace_index] == activity) {
+		activity_trace_cnt[activity_trace_index]++;
+	} else {
+		activity_trace_index = (activity_trace_index + 1)
+			% ACTIVITY_TRACE_ITEMS;
+		activity_trace[activity_trace_index] = activity;
+		activity_trace_cnt[activity_trace_index] = 0;
+
+		ptr = activity_trace_descr[activity_trace_index];
+		va_start(ap, fmt);
+		vsnprintf(ptr, TRACE_DESCR_LEN, fmt, ap);
+		va_end(ap);
+	}
+}
+#endif
+
+/******************************************************************************
+ * World-switch ring-buffer
+ */
+
+#define WS_TRACE_ITEMS 10
+static u32 ws_trace_enter[WS_TRACE_ITEMS];
+static int ws_trace_enter_index = 0;
+static u32 ws_trace_exit[WS_TRACE_ITEMS];
+static int ws_trace_exit_index = 0;
+static u32 ws_trace_exit_codes[WS_TRACE_ITEMS];
+DEFINE_MUTEX(ws_trace_mutex);
+
+void trace_ws_enter(u32 guest_pc)
+{
+	mutex_lock(&ws_trace_mutex);
+	ws_trace_enter[ws_trace_enter_index++] = guest_pc;
+	if (ws_trace_enter_index >= WS_TRACE_ITEMS)
+		ws_trace_enter_index = 0;
+	mutex_unlock(&ws_trace_mutex);
+}
+
+void trace_ws_exit(u32 guest_pc, u32 exit_code)
+{
+	mutex_lock(&ws_trace_mutex);
+	ws_trace_exit[ws_trace_exit_index] = guest_pc;
+	ws_trace_exit_codes[ws_trace_exit_index++] = exit_code;
+	if (ws_trace_exit_index >= WS_TRACE_ITEMS)
+		ws_trace_exit_index = 0;
+	mutex_unlock(&ws_trace_mutex);
+}
+
+void print_ws_trace(void)
+{
+	int i;
+	mutex_lock(&ws_trace_mutex);
+
+	if (ws_trace_enter_index != ws_trace_exit_index) {
+		kvm_msg("enter and exit WS trace count differ");
+		mutex_unlock(&ws_trace_mutex);
+		return;
+	}
+
+	/* Avoid potential endless loop */
+	if (ws_trace_enter_index < 0 || ws_trace_enter_index >= WS_TRACE_ITEMS) {
+		kvm_msg("ws_trace_enter_index out of bounds: %d",
+				ws_trace_enter_index);
+		mutex_unlock(&ws_trace_mutex);
+		return;
+	}
+
+	for (i = ws_trace_enter_index - 1; i != ws_trace_enter_index; i--) {
+		if (i < 0) {
+			i = WS_TRACE_ITEMS;
+			continue;
+		}
+
+		printk(KERN_ERR "Enter: %08x    Exit: %08x (%d)\n",
+			ws_trace_enter[i],
+			ws_trace_exit[i],
+			ws_trace_exit_codes[i]);
+	}
+	mutex_unlock(&ws_trace_mutex);
+}
+
+/******************************************************************************
+ * Dump total debug info, or write to /proc/kvm
+ */
+
+struct kvm_vcpu *latest_vcpu = NULL;
+
+void print_kvm_debug_info(int (*print_fn)(print_fn_args), struct seq_file *m)
+{
+	int i;
+	struct kvm_vcpu_regs *regs;
+	char *mode = NULL;
+	char *exceptions[7];
+	struct kvm_vcpu *vcpu = latest_vcpu;
+	struct kvm_event_order *ptr;
+
+	print_fn(m, "KVM/ARM runtime info\n");
+	print_fn(m, "======================================================");
+	print_fn(m, "\n\n");
+
+	if (vcpu == NULL) {
+		print_fn(m, "No registered VCPU\n");
+		goto print_ws_hist;
+	}
+
+
+	switch (vcpu_mode(vcpu)) {
+		case MODE_USR:	mode = "USR"; break;
+		case MODE_FIQ:	mode = "FIQ"; break;
+		case MODE_IRQ:	mode = "IRQ"; break;
+		case MODE_SVC:	mode = "SVC"; break;
+		case MODE_ABT:	mode = "ABT"; break;
+		case MODE_UND:	mode = "UND"; break;
+		case MODE_SYS:	mode = "SYS"; break;
+	}
+
+	vcpu_load(vcpu);
+	regs = &vcpu->arch.regs;
+
+	print_fn(m, "Virtual CPU state:\n\n");
+	print_fn(m, "PC is at: \t%08x\n", vcpu_reg(vcpu, 15));
+	print_fn(m, "CPSR:     \t%08x\n(Mode: %s)  (IRQs: %s)  (FIQs: %s) "
+		      "  (Vec: %s)\n",
+		      regs->cpsr, mode,
+		      (regs->cpsr & PSR_I_BIT) ? "off" : "on",
+		      (regs->cpsr & PSR_F_BIT) ? "off" : "on",
+		      (regs->cpsr & PSR_V_BIT) ? "high" : "low");
+
+	for (i = 0; i <= 12; i++) {
+		if ((i % 4) == 0)
+			print_fn(m, "\nregs[%u]: ", i);
+
+		print_fn(m, "\t0x%08x", vcpu_reg_m(vcpu, i, MODE_USR));
+	}
+
+	print_fn(m, "\n\n");
+	print_fn(m, "Banked registers:  \tr13\t\tr14\t\tspsr\n");
+	print_fn(m, "-------------------\t--------\t--------\t--------\n");
+	print_fn(m, "             USR:  \t%08x\t%08x\t////////\n",
+			vcpu_reg_m(vcpu, 13, MODE_USR),
+			vcpu_reg_m(vcpu, 14, MODE_USR));
+	print_fn(m, "             SVC:  \t%08x\t%08x\t%08x\n",
+			vcpu_reg_m(vcpu, 13, MODE_SVC),
+			vcpu_reg_m(vcpu, 14, MODE_SVC),
+			vcpu_spsr_m(vcpu, MODE_SVC));
+	print_fn(m, "             ABT:  \t%08x\t%08x\t%08x\n",
+			vcpu_reg_m(vcpu, 13, MODE_ABT),
+			vcpu_reg_m(vcpu, 14, MODE_ABT),
+			vcpu_spsr_m(vcpu, MODE_ABT));
+	print_fn(m, "             UND:  \t%08x\t%08x\t%08x\n",
+			vcpu_reg_m(vcpu, 13, MODE_UND),
+			vcpu_reg_m(vcpu, 14, MODE_UND),
+			vcpu_spsr_m(vcpu, MODE_UND));
+	print_fn(m, "             IRQ:  \t%08x\t%08x\t%08x\n",
+			vcpu_reg_m(vcpu, 13, MODE_IRQ),
+			vcpu_reg_m(vcpu, 14, MODE_IRQ),
+			vcpu_spsr_m(vcpu, MODE_IRQ));
+	print_fn(m, "             FIQ:  \t%08x\t%08x\t%08x\n",
+			vcpu_reg_m(vcpu, 13, MODE_FIQ),
+			vcpu_reg_m(vcpu, 14, MODE_FIQ),
+			vcpu_spsr_m(vcpu, MODE_FIQ));
+
+	print_fn(m, "\n");
+	print_fn(m, "fiq regs:\t%08x\t%08x\t%08x\t%08x\n"
+			  "         \t%08x\n",
+			vcpu_reg_m(vcpu, 8, MODE_FIQ),
+			vcpu_reg_m(vcpu, 9, MODE_FIQ),
+			vcpu_reg_m(vcpu, 10, MODE_FIQ),
+			vcpu_reg_m(vcpu, 11, MODE_FIQ),
+			vcpu_reg_m(vcpu, 12, MODE_FIQ));
+
+print_ws_hist:
+	/*
+	 * Print world-switch trace circular buffer
+	 */
+	print_fn(m, "\n\nWorld switch history:\n");
+	print_fn(m, "---------------------\n");
+	mutex_lock(&ws_trace_mutex);
+
+	if (ws_trace_enter_index != ws_trace_exit_index ||
+			ws_trace_enter_index < 0 ||
+			ws_trace_enter_index >= WS_TRACE_ITEMS)
+	{
+		mutex_unlock(&ws_trace_mutex);
+		goto print_trace_activity;
+	}
+
+	exceptions[0] = "reset";
+	exceptions[1] = "undefined";
+	exceptions[2] = "software";
+	exceptions[3] = "prefetch abort";
+	exceptions[4] = "data abort";
+	exceptions[5] = "irq";
+	exceptions[6] = "fiq";
+
+	for (i = ws_trace_enter_index - 1; i != ws_trace_enter_index; i--) {
+		if (i < 0) {
+			i = WS_TRACE_ITEMS;
+			continue;
+		}
+
+		print_fn(m, "Enter: %08x    Exit: %08x (%s)\n",
+			ws_trace_enter[i], ws_trace_exit[i],
+			exceptions[ws_trace_exit_codes[i]]);
+	}
+	mutex_unlock(&ws_trace_mutex);
+
+print_trace_activity:
+#ifdef KVM_TRACE_ACTIVITY
+	/*
+	 * Print activity trace
+	 */
+	print_fn(m, "\n\nActivity circular buffer:\n");
+	print_fn(m, "-----------------------------\n");
+	for (i = activity_trace_index - 1; i != activity_trace_index; i--) {
+		if (i < 0) {
+			i = ACTIVITY_TRACE_ITEMS;
+			continue;
+		}
+
+		print_fn(m, "%lu: \t %s\n",
+				activity_trace_cnt[i],
+				activity_trace_descr[i]);
+	}
+#endif
+
+	/*
+	 * Print event counters sorted
+	 */
+	print_fn(m, "\n\nEvent counters:\n");
+	print_fn(m, "-----------------------------\n");
+	ptr = sort_kvm_event_log();
+	while (ptr != NULL) {
+		if (ptr->event->cnt > 0) {
+			print_fn(m, "%12llu  #  %s\n", ptr->event->cnt,
+							ptr->event->descr);
+		}
+		ptr = ptr->next;
+	}
+
+	if (vcpu != NULL) {
+		vcpu_put(vcpu);
+	}
+}
+
+static int __printk_relay(struct seq_file *m, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	vprintk(fmt, ap);
+	va_end(ap);
+	return 0;
+}
+
+void kvm_dump_vcpu_state(void)
+{
+	print_kvm_debug_info(&__printk_relay, NULL);
+}
+
+/******************************************************************************
+ * Printk-log-wrapping functionality
+ */
+
+#define TMP_LOG_LEN 512
+static char __tmp_log_data[TMP_LOG_LEN];
+DEFINE_MUTEX(__tmp_log_lock);
+void __kvm_print_msg(char *fmt, ...)
+{
+	va_list ap;
+	unsigned int size;
+
+	mutex_lock(&__tmp_log_lock);
+
+	va_start(ap, fmt);
+	size = vsnprintf(__tmp_log_data, TMP_LOG_LEN, fmt, ap);
+	va_end(ap);
+
+	if (size >= TMP_LOG_LEN)
+		printk("Message exceeded log length!\n");
+	else
+		printk("%s", __tmp_log_data);
+
+	mutex_unlock(&__tmp_log_lock);
+}
diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h
new file mode 100644
index 0000000..020240a
--- /dev/null
+++ b/arch/arm/kvm/trace.h
@@ -0,0 +1,108 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ *
+ *
+ * This file contains debugging and tracing functions and definitions for KVM/ARM.
+ *
+ */
+#ifndef __ARM_KVM_TRACE_H__
+#define __ARM_KVM_TRACE_H__
+
+#include <linux/types.h>
+#include <linux/kvm_types.h>
+#include <linux/kvm_host.h>
+
+#define EVENT_GUEST_ENTER	0
+#define EVENT_GUEST_EXIT	1
+#define EVENT_VCPU_BLOCK	2
+#define EVENT_IRQ_WINDOW	3
+#define EVENT_SWITCH_MODE	4
+#define EVENT_VCPU_IRQS_ON	5
+#define EVENT_VCPU_IRQS_OFF	6
+#define EVENT_WFI		7
+#define EVENT_FLUSH_SHADOW	8
+#define EVENT_MOD_TTBR		9
+#define EVENT_READ_GUEST_ENTRY	10
+#define EVENT_MAP_GVA_TO_GFN	11
+#define EVENT_DACR_CHANGE	12
+#define EVENT_SWITCH_PRIV	13
+#define EVENT_SWITCH_USER	14
+#define EVENT_VCPU_ASID		15
+#define EVENT_LS_TRANS		16
+#define EVENT_EMUL_MRS		17
+#define EVENT_EMUL_MSR		18
+#define EVENT_EMUL_CPS		19
+#define EVENT_NEED_RESCHED	20
+#define EVENT_MCR_7_5_0		21
+#define EVENT_MCR_7_5_1		22
+#define EVENT_MCR_7_5_2		23
+#define EVENT_MCR_7_5_7		24
+#define EVENT_MCR_7_6_0		25
+#define EVENT_MCR_7_6_1		26
+#define EVENT_MCR_7_6_2		27
+#define EVENT_MCR_7_7_0		28
+#define EVENT_MCR_7_10_0	29
+#define EVENT_MCR_7_10_1	30
+#define EVENT_MCR_7_10_4	31
+#define EVENT_MCR_7_14_0	32
+#define EVENT_MCR_7_14_1	33
+#define EVENT_MCR_7_15_0	34
+#define EVENT_MCR_8_5_X		35
+#define EVENT_MCR_8_6_X		36
+#define EVENT_MCR_8_7_X		37
+#define EVENT_EMUL_LSMULT	38
+
+#define KVM_EVENTC_ITEMS	39
+
+void kvm_arm_init_eventc(void);
+void kvm_arm_count_event(unsigned int event);
+void kvm_dump_vcpu_state(void);
+
+void trace_ws_enter(u32 guest_pc);
+void trace_ws_exit(u32 guest_pc, u32 exit_code);
+
+
+#define print_fn_args struct seq_file *, const char *, ...
+void print_kvm_debug_info(int (*print_fn)(print_fn_args), struct seq_file *m);
+
+
+void __kvm_print_msg(char *_fmt, ...);
+
+#define kvm_err(err, fmt, args...) do {			\
+	__kvm_print_msg(KERN_ERR "KVM error [%s:%d]: (%d) ", \
+			__FUNCTION__, __LINE__, err); \
+	__kvm_print_msg(fmt "\n", ##args); \
+} while (0)
+
+#define __kvm_msg(fmt, args...) do {			\
+	__kvm_print_msg(KERN_ERR "KVM [%s:%d]: ", __FUNCTION__, __LINE__); \
+	__kvm_print_msg(fmt, ##args); \
+} while (0)
+
+#define kvm_msg(__fmt, __args...) __kvm_msg(__fmt "\n", ##__args)
+
+
+#define KVMARM_NOT_IMPLEMENTED() \
+   { \
+	    printk(KERN_ERR "KVM not implemented [%s:%d] in %s \n", \
+		   __FILE__, __LINE__, __FUNCTION__); \
+   }
+
+extern bool trace_gva_to_gfn;
+void print_shadow_mapping(struct kvm_vcpu *vcpu, gva_t gva);
+void print_ws_trace(void);
+void kvm_trace_activity(unsigned int activity, char *fmt, ...);
+
+#endif  /* __ARM_KVM_TRACE_H__ */
diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig
index cfbc0f1..5b00905 100644
--- a/arch/arm/mach-vexpress/Kconfig
+++ b/arch/arm/mach-vexpress/Kconfig
@@ -33,6 +33,7 @@ config ARCH_VEXPRESS_CA15X4
 	bool "Versatile Express Cortex-A15x4 tile"
 	depends on VEXPRESS_EXTENDED_MEMORY_MAP
 	select CPU_V7
+	select ARM_VIRT_EXT
 	select ARM_GIC
 	select HAVE_ARCH_TIMERS
 
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 04de742..ad77805 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -628,6 +628,13 @@ config ARM_LPAE
 	  Say Y if you have an ARMv7 processor supporting the LPAE page table
 	  format and you would like to access memory beyond the 4GB limit.
 
+config ARM_VIRT_EXT
+	bool "Support for ARM Virtualization Extensions"
+	depends on ARM_LPAE
+	help
+	  Say Y if you have an ARMv7 processor supporting the ARM hardware
+	  Virtualization extensions.
+
 config ARCH_PHYS_ADDR_T_64BIT
 	def_bool ARM_LPAE
 
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index ea2dc1a..d2ab07e 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -310,6 +310,7 @@ struct kvm_translation {
 struct kvm_interrupt {
 	/* in */
 	__u32 irq;
+	__u8  raise;
 };
 
 /* for KVM_GET_DIRTY_LOG */